Amy is in love with her teacher and when she finds out that her dad has made a time machine, the Szalinski Time Hopper, she decides to go back to the 70s to meet her teacher, when he was 17. She goes back but to 1976 and after numerous attempts decides not to return. Nick tells his dad, who goes back in time to rescue her before she suffers the ill effects of temporal displacement. While Wayne is in the past, he runs into teen-aged Diane and he figures out how to make up for both a forgotten wedding anniversary and a Time Hopper problem.

When Wayne invents a neuron nudger, Diane accidentally turns it on and swaps her brain with that of Bianca's cat. Bianca, Wayne's scheming coworker, switches Wayne's brain with Quark's so she can use Wayne's body to access his vault at work. Nick and Amy then try to switch Wayne, Diane, and Bianca's brain back to their correct bodies.